Hitherto, conventional sprinkler nozzles are structured so as to form such sprinkling patterns by dividing their nozzles into two sprinkling paths, opening the two sprinkling paths independently from each other or together, and adjusting the extent of the opening of the sprinkling paths, as described, for example, in Japanese Utility Model Publication No. 6-26,366 or U.S. Pat. No. 4,785,998. More specifically, such conventional sprinkler nozzles are configured such that water flowing from a holding cylinder is sprinkled in a shower state from an outer periphery of a nozzle body via through holes disposed through a peripheral wall of the nozzle body and further that the water is sprinkled in a straight state when the shower flow paths from the through holes are closed and changed to the straight flow paths by sliding a sealing member for changing the flow paths from the through holes.
With such an arrangement of the nozzles, the shower flow path and the straight flow path are arranged in such a manner that an inner cylinder is disposed to surround an outer periphery of the nozzle body with the through holes disposed through the peripheral wall thereof to form a clearance between the nozzle body and the inner cylinder as a flow path for outflowing water through the clearance in a straight state or spraying water and to form a clearance outside the inner cylinder as a shower flow path.
Further, the entire inner cylinder is structured in a state in which the inner cylinder is connected integrally to a base end of an outer casing disposed on the outer peripheral side of the inner cylinder.
Moreover, Japanese Utility Model Publication No. 5-1,319 discloses a sprinkler nozzle which is structured such that a flow path is divided into fine sections so as to provide four or more kinds of sprinkling patterns.
More specifically, the sprinkler nozzle is structured in such a way that a tip end portion of a main flow path of the sprinkling nozzle body is closed with a flow path extending from the rear portion of the closed wall and a flow path extending from the front portion thereof disposed as a basic flow path and that each flow path is further divided into plural sections to form a large number of flow paths. Further, this prior art sprinkling nozzle is so arranged as to form four kinds of such sprinkling patterns or more by adjusting the positions of inflow holes disposed on the main flow path while moving them in a forward or backward direction.
On the other hand, the sprinkler nozzle as disclosed in Japanese Utility Model Publication No. 6-26,366 or U.S. Pat. No. 4,785,998 is so structured so as to provide a sprinkling pattern, such as, in a shower, in a straight state, in a mist or the like by moving the inner cylinder in a forward or backward direction. However, particularly when water is sprayed in a mist state, there is the risk that a central portion of the water being sprinkled in a mist state is likely to become hollow, thereby forming a circle-shaped sprinkling pattern. Further, when water is sprinkled in a spraying state, there is the risk that the sprinkling distance may become extremely short. There have so far been no such sprinkler nozzles in which only one sprinkler nozzle itself can solve those defects as the conventional sprinkler nozzles have and at the same time can in turn sprinkle water in various sprinkling patterns, such as, in a mist state, in a cone-shaped form, a straight rod-shaped form, in a funnel-shaped form, in a shower state, in a circular state, in a fan-shaped form, or the like.
Moreover, those prior art sprinkler nozzle present the defects that, when a tip end portion of the nozzle body causes clogging or it is damaged, it is difficult to inspect and a damaged part of the inner cylinder should be replaced as a whole. Further, when they are assembled together, an increased number of steps for fixing the parts to each other is required so that the assembly operation becomes more complicated by the addition of those steps. Moreover, although such various sprinkling patterns can be created, they suffer from the disadvantages in terms of maintenance.
Furthermore, the sprinkler nozzle as disclosed in Japanese Utility Model Publication No. 5-1,319 may present the risks that a definite shift of the sprinkling patterns cannot be carried out because each flow path is not partitioned in a definite way so that the water flow may be mixed together in an intermediate position and that water fails to flow smoothly or a sprinkling force upon sprinkling may be hindered because there are many irregular surface portions at connection sections of each member in an intermediate region of the flow path.
The present invention has been carried out to solve the defects and disadvantages inherent in those conventional sprinkler nozzles as described hereinabove by providing a sprinkler nozzle that can sprinkle water in a variety of sprinkling patterns and that allows a flow path to be partitioned in a definite way, thereby allowing water to flow in a smooth way and reducing a flow load in a sprinkling direction as low as possible.